Hey Mark,The main thing is to be diligent on maintenance.High pressure oil pumps,coolant leaks,radiators.The 6.4 was much improved over the 6.0,but still see some issues that are common.If you have an extended warrenty good if not engine and drive train are covered for 100,000.We see more issues from guys that just run trucks hard and are lax on maintenance and that is not good.Most people that are not making a living with truck and mostly pulling toys do not normally have major issues.